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Natural Heritage Bald & Endangered Haliaeetus leucocephalus

Program State Status: Special Concern www.mass.gov/nhesp Federal Status: None Massachusetts Division of Fisheries &

DESCRIPTION: The is one of the most impressive and majestic in North America. It is one of eight species in the Haliaeetus, the "" or "sea" , and is the only member of the genus that occurs regularly in North America. This species is one member of the of Accipiters, all of which are in the order Falconiformes. It is also the largest raptor ( of prey) in Massachusetts, attaining a wingspan of 2.0 to 2.2 meters (6.5 to 7.0 feet) with a body length of 0.9 meters (3.0 feet), and a weight ranging from 3.6 to 6.6 kilograms (8 to 15 lbs.) at maturity. The sexes are similar in appearance but, as with most raptor species, the females are notably larger than the males. Photo by Bill Byrne, MassWildlife Adult Bald Eagles are distinctively colored with a white head and , brown body, pale yellow eyes, and bright yellow and feet. The adult is attained at 4 eye and beak color also change with age, from dark to 5 of age. The plumage of immature Bald Eagles brown and blackish-gray at hatching to bright yellow in adults. In all feathered stages, the tail is rounded and the may vary considerably. Immatures go through a sequence of plumage types before reaching maturity. lower half of the tarsus is unfeathered.

These include a uniformly dark phase in the first , followed by phases with various amounts of Bald Eagles fly with heavy, deep strokes and soar on flattened wings. In silhouette, the beak, head, and neck white on the belly, back, underwings, tail, and head. The are almost as long as the tail.

SIMILAR SPECIES IN MASSACHUSETTS: The large size and distinctive plumage of the Bald Eagle make it very easy to distinguish from all other birds in Massachusetts, with the exception of the ( chrysaetos). Both grow to approximately the same size, but the white head and tail of the adult Bald Eagle differentiates it from the Golden Eagle. Immature Bald Eagles may be confused with both immature and adult Golden Eagles. The adult Golden Eagle is nearly Cumulative Nesting Distribution in uniformly dark without the mottling found on the Massachusetts immature Bald Eagle. Golden Eagles at any age may 1990-2015 have relatively sharply defined, bright, clean white Based on records in patches of varying size at the base of the inner primaries Natural Heritage Database and outer secondaries on the wings and a clean white

A Species of Greatest Conservation Need in the Massachusetts State Wildlife Action Plan Massachusetts Division of Fisheries & Wildlife 1 Hill Rd., Westborough, MA; tel: 508-389-6300; fax: 508-389-7890; www.mass.gov/dfw

Please allow the Natural Heritage & Program to continue to conserve the biodiversity of Massachusetts with a contribution for ‘endangered wildlife conservation’ on your state income tax form, as these donations comprise a significant portion of our operating budget. www.mass.gov/nhesp Bald Eagle Fact Sheet – p. 2 area at the base of the tail. All immature Bald Eagles adequate supply of moderate-sized to large fish, an have whitish axillaries and, depending on age, can have unimpeded view, and reasonable freedom from human extensive, “dirty” white mottling virtually anywhere on disturbance. Wintering eagles require suitable roost trees the head, body, wing linings, and tail. The Golden for night roosting. Some such roosts may be 20 km or Eagle’s legs are feathered to its toes; the legs of the Bald more from feeding areas, occurring in favorable thermal Eagle are unfeathered. environments where roost trees are protected from the wind by topography or other trees. The use of these The Turkey is similar to an immature Bald protected sites helps minimize the energy stress Eagle in size and general coloration. At a distance, a encountered by wintering birds. The absence of a distinction can be made by looking at the birds as they suitable night roost could limit the use of otherwise soar. Turkey hold their wings somewhat suitable habitat. upright, forming a shallow "V" when soaring and rock from side to side as they ride thermal air currents. Bald LIFE CYCLE/BEHAVIOR: Courtship occurs in mid- Eagles hold their wings straight out from their body to late winter and is a spectacular sight consisting of while soaring, with only the tips of the primary aerial loops, cartwheels, dives, and ending with the curved slightly upward. Eagles do not rock from side to prospective mating pair locking their talons together and side as they soar, but rather make broad, sweeping diving straight downward for hundreds of feet while circles as updrafts lift them skyward. At close range, the spinning head over heels. Bald Eagles may live up to 30 's small, featherless head (which is red in years, but mortality is relatively high in the immature adults and gray in juveniles) makes identification quite age classes. They mate for life, but if one member of a simple. pair dies or is killed, the other will actively court another mate. Sexual maturity is reached at four to six years of RANGE: Bald Eagles occur from and age, but the birds may be considerably older before they south throughout the to and Baja breed for the first time. . In the lower 48 states, they occur sporadically over a wide area with notable seasonal The breeding season for Bald Eagles in Massachusetts concentrations in Florida, the area, the begins with courtship during late fall or early winter. Mississippi Valley and . In After courtship, the mated pair builds a large during Massachusetts, occurrences are possible statewide, December–February. The nest is constructed with large especially during migration in March-April and sticks and lined with sprigs of , grasses, and other September-October; however, wanderers can appear soft materials. The male eagle collects the nest material virtually anywhere at any time. In Massachusetts, Bald and delivers it to his mate, who is responsible for most Eagles use the Quabbin Reservoir, the Connecticut of the actual nest construction. Once the nesting site is , the Merrimack River, and the Assawompsett chosen, the mated pair will usually return every year to Pond complex throughout the year as both nesting and the same site and add to the existing structure. The wintering habitat. Bald Eagles also overwinter along the are located in hardwoods or from 9 to 37 meters of Cape Cod, 's Bay and the islands of (30 to 120 feet) above the ground and may measure up Martha's Vineyard and Nantucket. Historically, the Bald to 3.6 meters (12 feet) high and 2.6 meters (8.5 feet) Eagle bred throughout most of North America prior to wide, with a weight of hundreds of pounds. Trees its widespread, well-publicized population decline selected for nesting (and sometimes for roosting and during the early to mid-1900s. However, during the past perching) tend to be relatively large and, preferably, several decades, the Bald Eagle has recolonized much of taller than their surroundings. Ideally, the nest lies below its historic range and continues to repopulate areas the top of the crown in a live tree, where the young are where suitable habitat still exists. sheltered from the elements but the parent birds are still afforded adequate aerial access (generally, from the HABITAT IN MASSACHUSETTS: Bald Eagles direction of the nearest water). usually inhabit coastal areas, estuaries, and larger inland waters. This species requires a great amount of shoreline The female Bald Eagle lays one to three (two average) habitat containing stands of forest for nesting and trees dull white eggs several days apart, usually during a projecting above the forest canopy for perching, an period between early March and early April. The eggs

A Species of Greatest Conservation Need in the Massachusetts State Wildlife Action Plan

Please allow the Natural Heritage & Endangered Species Program to continue to conserve the biodiversity of Massachusetts with a contribution for ‘endangered wildlife conservation’ on your state income tax form, as these donations comprise a significant portion of our operating budget. www.mass.gov/nhesp Bald Eagle Fact Sheet – p. 3

are incubated (mostly by the female) for approximately forest to development and agriculture), the Bald Eagle 35 days until hatching. The eggs do not hatch at the decreased in numbers in much of its range for many same time, giving the first hatchling a significant years. From 1917 to 1952, at least 128,000 Bald Eagles advantage over its siblings. Competition for food is were believed to have been killed in Alaska where there intense, and if the adult eagles are not able to provide was a bounty on the species. In the 20th century, the enough for all of their young, the older chick will take introduction of man-made chemicals and pollutants to advantage of its greater strength and size to seize most of the environment was implicated in death, increased the food provided by the parents, causing its younger susceptibility to death, and diminished reproductive siblings to starve. This behavior increases the probability success of Bald Eagles. DDT and its metabolites, as well that at least one chick will survive. Young eaglets grow as other organochlorines, are well-documented causes of rapidly and may eat up to two pounds of fish per day. eggshell thinning, breakage, and toxicity. The Bald Ten weeks after hatching, they begin to make short Eagle was listed federally as an Endangered Species in flights from the nest, spending much time with the 1967. parent birds observing the adults as they catch and find food. By late fall the adults will no longer care for their A decline in human persecution and reductions in use of young, and the fledgling eaglets begin life on their own. DDT and other toxins are credited with recent recoveries The entire breeding cycle, from nest construction to of Bald Eagle populations during the past quarter- fledging of young, lasts 6–8 months. Most Bald Eagles century. The federal status of the species was upgraded appear to nest within 200 miles of where they hatched. to Threatened in 1995, and the species was removed from the federal list of threatened and endangered When available, fish (both marine and freshwater) is the species in August 2007. However, Bald Eagle Bald Eagle's preferred food. Fish may be captured by populations remain imperiled in a number of states, as swooping from a perch or by coursing low over the prior habitat loss, prior and current habitat degradation, water and dropping straight down when a fish is spotted. and ongoing disturbance from growing human An eagle may plunge into the water to capture fish and populations continue to limit population viability. may also steal fish from an by harassing it until it drops its catch. Prey too large to carry may be dragged to POPULATION STATUS IN MASSACHUSETTS: shore. Birds, especially waterfowl, are sometimes taken Breeding Bald Eagles were extirpated from by bursting into a large flock and pursuing a straggler Massachusetts during the early 1900s. However, from until it tires and can be captured. Bald Eagles also take 1982 to 1988, forty-one young Bald Eagles from crippled waterfowl and , small and Michigan and Canada were relocated to Quabbin , particularly dead fish. In winter, eagles of all Reservoir in Massachusetts. Following this restoration ages may gather in large numbers at areas with open effort, Bald Eagles were confirmed to breed successfully water where fish or waterfowl are abundant. This "social in the state by 1989. Eagle numbers have increased grouping" is believed to facilitate locating and acquiring slowly but steadily since that time. During 2015, an all- food and may possibly aid in establishing or maintaining time high of at least 51 pairs of Bald Eagles maintained pair bonds. breeding territories in Massachusetts: Quabbin Reservoir (7), Connecticut River (11), Merrimack River (3), HISTORICAL THREATS: The history of the Bald Assawonpsett Pond Complex (2), Westfield River (2), Eagle is one of human contradictions. On one hand, the Deerfield River (2), North Watuppa Pond (1), Wachusett Bald Eagle’s noble image has been portrayed on public Reservoir (1), Quaboag Pond (1), Swift River (1), documents, coin, currency, etc. as our nation's symbol Westfield River (1), Housatonic River (1), Onota since 1782, making it one of the most well-known (1), Lake Shirley (1), Pine Hill Reservoir (1), Webster creatures on earth. On the other hand, its environment Lake (1), Foss Reservoir (1), Halfway Pond (1), has been reduced and degraded, and the bird itself was Powwow River (1), Lake Buel (1), Tully Lake (1), treated as vermin throughout North America for the Blackstone River (1), Big Pond (1), Suntaug Lake (1), better part of a century. As a result of deliberate killing Chicopee River (1), Housatonic River (1), Charles River by people (who incorrectly believed that eagles kill (1), Westport River (1), Quinebaug River (1), Round livestock or significantly threaten fisheries), Pond (1), Neponset River (1), and Mashpee Pond (1). combined with substantial habitat loss (conversion of Although we no longer conduct a winter survey, during

A Species of Greatest Conservation Need in the Massachusetts State Wildlife Action Plan

Please allow the Natural Heritage & Endangered Species Program to continue to conserve the biodiversity of Massachusetts with a contribution for ‘endangered wildlife conservation’ on your state income tax form, as these donations comprise a significant portion of our operating budget. www.mass.gov/nhesp Bald Eagle Fact Sheet – p. 4 the 2008 Midwinter Bald Eagle Survey, 72 Bald Eagles Population monitoring at both the state and regional were counted in Massachusetts: Quabbin Reservoir (36), level will be an important tool to help determine Merrimack River (8), Connecticut River (9), Wachusett population status, growth potential, and possible Reservoir (5), Lake Assawompsett (4), and other sites conservation setbacks. With continued sound (10). Population abundance in Massachusetts is limited management and increased public awareness, the future mainly by amount of potential breeding habitat (i.e., of the Bald Eagle should continue to be one of number of large water bodies surrounded by mature conservation's greatest success stories. forest and having shallow waters and abundant fish). Population viability is limited mainly by the species’ rarity and the possibility of catastrophic events (e.g., REFERENCES: storms, disease). Bonney, R.E., Jr., J.W. Kelley, D.J. Decker, and R.A. Howard, Jr. 1981. Understanding Predation and Northeastern MANAGEMENT RECOMMENDATIONS: Birds of Prey. Ithaca, N.Y.: N.Y. State College of Protection and enhancement of potentially suitable Agriculture/Cornell University. and forest habitats, and maintenance of known Buehler, D.A. 2000. Bald Eagle. No. 506 in A. Poole and F. Gill, editors. The Birds of North America. Academy of breeding, roosting, and wintering areas will be critical to Natural Sciences, , , and long-term conservation of Bald Eagles in Massachusetts. American Ornithologists’ Union, , D.C., To achieve these objectives, landowners should first USA. work to limit development near shorelines of large water Clark, W.S., and B.K. Wheeler. 1987. A Field Guide to bodies, as loss of nesting habitat is a primary threat to of North America. Houghton Mifflin Company, Boston. Bald Eagles in the state. Prevention, identification, and Fraser, J.D. 1985. The impact of human activities on Bald remediation of environmental contamination (e.g., lead, Eagle populations – a review. Pages 68–84 in J. M. mercury, PCBs, and other toxic depositions) are also key Gerrard and T. M. Ingram, editors. The Bald Eagle in to maintaining adequate foraging habitat and Canada. White Horse Plains Publishing, Headingley, maximizing long-term reproductive success and survival , Canada. Fraser, J.D., L.D. Frenzel, and J.E. Mathisen. 1985. The of Bald Eagles. Landowners who wish to harvest timber impact of human activities on breeding Bald Eagles in near potential eagle habitat should consult the north-central . Journal of Wildlife Massachusetts Forestry Conservation Management Management 49:585–592. Practices (CMPs) for Bald Eagle; these practices, which Johnsgard, P.A. 1990. Hawks, Eagles, and of North are published by the Natural Heritage and Endangered America. Smithsonian Institution Press, Washington, Species Program, provide guidance for protecting (or D.C. even enhancing) nesting and foraging habitat during Nisbet, I.C.T. 1989. Organochlorines, reproductive forestry projects. Increased public education about the impairment, and declines in Bald Eagle Haliaeetus potentially detrimental effects of human disturbance on leucocephalus populations: mechanisms and dose reproductive success of Bald Eagles is another measure relationships. Pages 483–489 in B. U. Meyburg and R. D. Chancellor, editors. Raptors in the Modern World. that can be taken. World Working Group for Birds of Prey, Berlin, . Direct mortality does not appear to be a leading threat to Northern States Bald Eagle Recovery Team.1983. Northern long-term conservation of Bald Eagles in Massachusetts. States Bald Eagle Recovery Plan. U.S. Fish & Wildlife However, every effort should be made to prevent Service. Washington, D.C. avoidable deaths. Fishermen should be diligent in proper Palmer, R.S. 1962. Handbook of North American Birds. vol. disposal of fishing line and equipment; eagles are known IV. Yale University Press, New Haven. to accidentally ingest hooks, and at least one eaglet has Robards, F.C., and J.G. King. 1966. Nesting and productivity been killed in Massachusetts after becoming tangled in of Bald Eagles, – 1966. U. S. Bureau of fishing line. Bald Eagles are still taken by shooting on Sport Fisheries and Wildlife Report, Juneau, Alaska, USA. occasion; hence, education and strict law enforcement Stalmaster, M. 1987. The Bald Eagle. Universe Books, New are additional measures that can be taken to improve York. survival. Terres, J.K. 1991.The Society Encyclopedia of North American Birds. Wing Books, .

A Species of Greatest Conservation Need in the Massachusetts State Wildlife Action Plan

Please allow the Natural Heritage & Endangered Species Program to continue to conserve the biodiversity of Massachusetts with a contribution for ‘endangered wildlife conservation’ on your state income tax form, as these donations comprise a significant portion of our operating budget. www.mass.gov/nhesp Bald Eagle Fact Sheet – p. 5

Wiemeyer, S.N., C.M. Burick, and C.J. Stafford. 1993. Environmental contaminants in Bald Eagle eggs – 1980- 1984 – and further interpretations of relationships to productivity and shell thickness. Archives of Environmental Contamination and Toxicology 13:529– 549.

Updated 2019

A Species of Greatest Conservation Need in the Massachusetts State Wildlife Action Plan

Please allow the Natural Heritage & Endangered Species Program to continue to conserve the biodiversity of Massachusetts with a contribution for ‘endangered wildlife conservation’ on your state income tax form, as these donations comprise a significant portion of our operating budget. www.mass.gov/nhesp